Alona Banai albanai@u.northwestern.edu Graduate Student Masters Program in Plant Biology & Conservation Northwestern University and the Chicago Botanic Garden
Figure1: L. leptostachya		Research Interests I am studying the putative hybridization between the federally threatened prairie legume, Prairie Bush Clover, Lespedeza leptostachya Englem. and its co-occurring congener, the common Round Headed Bush Clover, L. capitata Michx.
		Hybridization occurs frequently in nature, especially in the plant kingdom (Rhymer and Simberloff 1996). The 23,675 hybrid plants identified represent an underestimate of the actual number of natural hybrids (Knobloch 1972). Hybridization can have both beneficial and harmful consequences (Fant et al. 2001). Hybridization can generate new species (speciation); however it can also lead to genetic dilution which can cause the extinction of a rare species. The problem of interspecific hybridization in rare plants is heightened because rare species tend to occur in low numbers and more frequently near larger populations of congener species (Levin et al. 1996).			Figure 2: L. capitata
The negative consequences of hybridization include: 1. Genetic introgression; defined as dilution of a rare species gene pool with another species alleles (usually via backcrossing) (Rhymer and Simberloff 1996). 2. Disruption of co-adapted gene complexes producing less fit offspring. 3. Wasted reproductive effort leading to the proliferation of hybrids at the expense of the rare plant (Levin et al. 1996). 4. Hybrid vigor/heterosis in which hybrids have higher survival rates than their parents (Rhymer and Simberloff 1996). 5. Hybrid swarm in which hybrid offspring successfully outcompete the parental plants. 6. Extinction; the final and most negative consequence due to the result of all or a combination of the above (Levin et al. 1996). Natural hybridization is common in the genus Lespedeza (Clewell 1966) and has been identified as one of the possible threats to the federally threatened Prairie Bush Clover, Lespedeza leptostachya Englem (Fabaceae). In America, the 12 native Lespedeza species have overlapping ranges (Clewell 1966); this includes L. leptostachya which often co-occurs with its native common congener, L. capitata Michx. (Cole and Biesboer 1992, Herkert and Ebinger 2002). Observations of L. leptostachya and L. capitata in the field suggest that hybridization might occur in many of their shared habitats (Banai, Bittner, Sather, Watson, and Vitt personal observations). This is surprising given that L. leptostachya is known to primarily reproduces by selfing via cliestogamous flowers (Sather 1990) and produces few chasmogamous flowers resulting in a low probability of pollination via outcrossing let alone hybridization (Sather 1990). In Minnesota L. leptostachya produces more chasmogamous flowers and in those locations putative hybrids have been observed. However, hybrids between L. leptostachya and L. capitata are not formally recognized by the current published dichotomous keys (Gleason, and Cronquist. 1991). Due to the threatened status of L. leptostachya there is a need to establish if hybridization is occurring in order to protect the genetic integrity of this species.
Figure 3: Leaves and flowers (to scale) collected in the field showing the intermediate morphological traits which characterize the putative hybrid. L. leptostachya (left) Hybrid (center), L. capitata (right)				Figure 4: Discriminate Analysis (JMP software) showing distinct morphological differentiation between the parent species and putative hybrid.
In my research, I plan to measure genetic and quantify morphological differences between L. leptostachya, L. capitata and their putative hybrid to establish of hybridization is occurring in Minnesota. Working with Dr. Kayri Havens, Dr. Jeremie Fant, and Dr. Pati Vitt. I am using a two fold approach to ask: is hybridization occurring between L. leptostachya and L. capitata? 1. Using DNA extracted from leaf tissue collected throughout the ranges of L. leptostachya and L. capitata, I will try to identify species specific cpDNA and nuclear markers to compare to that of the putative hybrid. 2. I will use morphological measurements taken from 8 field sites in Minnesota to identify morphological differences between the parental species and their putative hybrid, and distinguish key characteristics to identify the hybrids from their parents in the field.
About Me I was born and raised in Israel for six years before moving to Urbana IL and subsequently to Chicago. I graduated magna cum laude from Washington University in St. Louis with a BA in Environmental Studies and Hebrew in 2002. My undergraduate honor’s thesis research, with Dr. Tiffany Knight, focused on the population viability of rare and common Linanthus (Polemoniaceae) species. Currently, besides student life, I am an active and competitive road racer. I also teach Hebrew School and am the president of NU JOT (Northwestern University Jews Over Twenty).
Posters & Publications Poster: Explaining Rarity Among Rare and Common Linanthus Species. 2006. Ecological Society of America Annual Meeting, Memphis, TN Poster: Pollination Biology of Rare and Common Linanthus Species. 2005. Howard Hughes Medical Institute Research Symposium, St. Louis, MO References Clewell, A.F. 1966. Identification of the Lespedezas in North America. Bulletin of Tall Timbers Research Station 7. 29pgs. Cole, C.T. and D.D. Biesboer. 1992. Monomorphism, reduced gene flow, and cleistogamy in rare and common species of lespedeza (Fabaceae). American Journal of Botany. 79(5): 567-575. Fant, J.B., C.D. Preston, and J.A. Barrett. 2001. Isozyme evidence of the parental origin and possible fertility of the hybrid Potamogeton x fluitans Roth. Plant Systematics and Evolution 229: 45-57. Gleason, H. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States. New York Botanical Garden Press, New York. Herkert, J.R. and J.E. Ebinger, Eds. 2002. Endangered and threatened species of Illinois: status and distribution; volume 1 – plants. Illinois Endangered Species Board, Springfield, IL, 161 pgs. Levin, D.A., J Francisco-Ortega, and R.K. Jansen. 1996. Hybridization and the extinction of rare plant species. Conservation Biology 10(1): 10-16. Sather, N. 1990. Prairie bush clover: a threatened Midwestern prairie plant. Minnesota Department of Natural Resources, St. Paul. 12 pgs. Awards and Honors 2007 USFWS Section Six Cooperative Endangered Species Conservation Fund Grant 2007 North Shore Garden Club Research Scholarship 2006 Harris Family Foundation Fellowship, Northwestern University and Chicago Botanic Garden 2006 Northwestern University Award in Plant Biology and Conservation 2006 Illinois Native Plant Society Research Grant Links of Interest Knight Lab Web Page (Undergraduate Research) CV
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